A method for controlling furnace pressure in isolation section of silicon steel continuous annealing furnace

Abstract

The invention provides a method for controlling the furnace pressure in the isolation section of a continuous annealing furnace for silicon steel. The furnace pressure P01 in the 1# furnace area, the furnace pressure P02 in the 2# furnace area and the furnace gas pressure in the 1# isolation section are measured by a pressure transmitter. P12 is sent to the PLC control system; the PLC control system executes the PID parameter fuzzy self-tuning program, calculates the PID parameters, and then outputs the MV from the PID controller, and sends it to the associated operation controller; at the same time, the PLC control system also uses the normal distribution function Obtain the correction coefficient J12 of the relief valve in the 1# isolation section, and finally calculate the output opening of the relief valve in the 1# isolation section through the associated calculation controller MV12=J12×MV, and assign the calculation result of MV12 to the relief valve in the 1# isolation section to adjust the isolation Section furnace gas furnace pressure. The invention reduces the frequency of starting the nitrogen protection program to reduce the interference to the pressure and atmosphere in the furnace under the condition of ensuring the airflow isolation function of the isolation section and the micro positive pressure state of the isolation section.

Description

technical field [0001] The invention belongs to the field of control methods for furnace section atmosphere barrier in silicon steel heat treatment process, and in particular relates to a furnace pressure control method in the isolation section of a silicon steel continuous annealing furnace. Background technique [0002] According to the heat treatment process of silicon steel, the dry atmosphere and wet atmosphere furnace section, the nitrogen-hydrogen mixed atmosphere furnace section with various ratios, the heating section and the cooling section all need to be isolated from the atmosphere. Pressure difference is achieved, so it is necessary to set up a sealing device for furnace pressure control. At present, the device used for the atmosphere isolation of the furnace section on the silicon steel line is composed of an isolation baffle, a release pipe and a release control valve, but the control method is single, mainly by forming a closed loop for adjustment of the furn...

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Problems solved by technology

At present, the device used for the atmosphere isolation of the furnace section on the silicon steel line is composed of an isolation baffle, a discharge pipe, and a discharge regulating valve, but the control method is single, and the main method is to form a closed loop to adjust the furnace pressure in the isolation section and the discharge regulating valve.

However, this control method has the following problems: first, a single closed-loop adjustment, it is difficult to ensure a good furnace pressure difference under any circumstances, and it is difficult to achieve good isolation of the atmosphere; At the same time, the pressure of the furnace section will inevitably cause fluctuations in the furnace pressure of the surrounding furnace sections. When the annealing furnace needs to configure isolation section control for the atmosphere of multiple furnace sections, the independent control method of this isolation section will inevitably lead to a larger furnace section. Pressure fluctuations, which in turn affect the gradient and stability of the furnace pressure

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